A forward-feed double-effect evaporator, having 10 m2 of heating surface in each effect, is used tokgconcentrate 1 of caustic soda solution from 10 per cent by mass to 30%. During a particular run,kNwhen the feed is at 373 kelvin (K), the pressures in the two calandrias are 375 and 180-respectively,m2while the condenser operates at 30m2kNFor these conditions, calculate:(a) the load on the condenser.(b) the steam economyc) the overall heat transfer coefficient in each effect. Would there have been any advantages in usingbackward feed in this case? Heat losses to the surroundings are negligible.ConcentrationBoiling point riseSpecific heat capacityHeat of dilution, kJ/kgwt %deg KkJ/kg K101.63.856.13.722.33015.03.649.35041.63.222.220

From given Dataλ0=2141 kJ/kgλ1=2211 kJ/kgλ2=2370 kJ/kgMaking heat balance around stage…

A forward-feed double-effect evaporator, having 10 m? of heating surface in each effect, is used to kg of caustic soda solution from 10 per cent by mass to 30%. During a particular run, concentrate 1 kN when the feed is at 373 kelvin (K), the pressures in the two calandrias are 375 and 180 respectively, while the condenser operates at 30 kN For these conditions, calculate: m2 (a) the load on the condenser. (b) the steam economy c) the overall heat transfer coefficient in each effect. Would there have been any advantages in using backward feed in this case? Heat losses to the surroundings are negligible. Concentration Boiling point rise Specific heat capacity Heat of dilution, kJ/kg wt % deg K kJ/kg K 10 1.6 3.85 20 6.1 3.72 2.3 30 15.0 3.64 9.3 50 41.6 3.22 2.2

A forward-feed double-effect evaporator, having 10 m? of heating surface in each effect, is used to kg of caustic soda solution from 10 per cent by mass to 30%. During a particular run, concentrate 1 kN when the feed is at 373 kelvin (K), the pressures in the two calandrias are 375 and 180 respectively, while the condenser operates at 30 kN For these conditions, calculate: m2 (a) the load on the condenser. (b) the steam economy c) the overall heat transfer coefficient in each effect. Would there have been any advantages in using backward feed in this case? Heat losses to the surroundings are negligible. Concentration Boiling point rise Specific heat capacity Heat of dilution, kJ/kg wt % deg K kJ/kg K 10 1.6 3.85 20 6.1 3.72 2.3 30 15.0 3.64 9.3 50 41.6 3.22 2.2

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.3DP

See similar textbooks

Similar questions

A forced-circulation triple-effect evaporator using forward feed is to be used to concentrated a 10 wt% NaOH solution entering at 37.8°C to50%. The steam used enters at 58.6 kPa gage. The absolute pressure in the vapor space of the third effect is 6.76 kPa. The feed rate is 13 608kg/h. The heat transfer coefficients are U1 = 6246, U2 = 3407, U3 = 2271 W/m2 -K. All effects have the same area. Calculate the surface area, steam consumption and steam economy.
Figure below shows a steam jet refrigeration system that produces chilled water in a flash chamber. The chamber is maintained at a pressure by the steam ejector, which removes the vapor generated by entraining it in the low-pressure jet and discharging into the condenser. The vacuum pump removes air and other non-condensable gases from the condenser shell. For the conditions shown on the figure, determine the make-up water and cooling water flow rates in kg/hr. Show diagrams if there are any
Figure below shows a steam jet refrigeration system that produces chilled water in a flash chamber. The chamber is maintained at a pressure by the steam ejector, which removes the vapor generated by entraining it in the low-pressure jet and discharging into the condenser. The vacuum pump removes air and other non-condensable gases from the condenser shell. For the conditions shown on the figure, determine the make-up water and cooling water flow rates in kg/hr. SHOW THE NEEDED DIAGRAMS FOR THE SOLUTION
Figure below shows a steam jet refrigeration system that produces chilled water in a flash chamber. The chamber is maintained at a pressure by the steam ejector, which removes the vapor generated by entraining it in the low-pressure jet and discharging into the condenser. The vacuum pump removes air and other non-condensable gases from the condenser shell. For the conditions shown on the figure, determine the make-up water and cooling water flow rates in kg/hr.
A four-effect evaporator is being considered for concentratinga fruit juice that has no appreciable boiling-point elevation.Steam is available at 143.27 kPa, and the boiling point of the product in the fourth effect is 45°C. The overall heat-transfer coeffi cients are 3000 W/(m 2 °C) in the fi rst effect, 2500W/(m2 °C) in the second effect, 2100W/(m2°C) in thethird effect, and 1800W/(m2°C) in the fourth effect. Calculatethe boiling-point temperatures of the product in the fi rst,second, and third effects. Assume the heating areas in all theeffects are equal to 50m2 each. The mass fl ow rate of steam tothe fi rst effect is 2400kg/h, the feed rate to the fi rst effect of 5%total solids fl uid is 15,000kg/h, the concentrated product fromthe fi rst effect leaves at 6.25% total solids, and the concentrationof product leaving the second effect is 8.82% total solids. Make it in the form of an example solution spreadsheet .....
8.3 A four-effect evaporator is being considered for concentratinga fruit juice that has no appreciable boiling-point elevation.Steam is available at 143.27 kPa, and the boiling point ofthe product in the fourth effect is 45°C. The overall heat-transfer coeffi cients are 3000 W/(m 2 °C) in the fi rst effect,2500W/(m2 °C) in the second effect, 2100W/(m2°C) in thethird effect, and 1800W/(m2°C) in the fourth effect. Calculatethe boiling-point temperatures of the product in the fi rst,second, and third effects. Assume the heating areas in all theeffects are equal to 50m2 each. The mass fl ow rate of steam tothe fi rst effect is 2400kg/h, the feed rate to the fi rst effect of 5%total solids fl uid is 15,000kg/h, the concentrated product fromthe fi rst effect leaves at 6.25% total solids, and the concentrationof product leaving the second effect is 8.82% total solids. Make it in the form of a spreadsheet for solving the example problem no. 8.2 and 8.3
The following data for steam con denser: Steam condensed =50000 kg/h; Temperature of steam in condenser = 40 oC; Dryness of steamentering into condenser=0.85; The air leakage in the condenser = 150 kg/h;Temperature of the condensate = 35oC. Find: (1) The air leakage pressure. (2)Quantity of cooling water passed through the condenser per hour if the rise incooling water temperature is limited to 10oC
Benzene at 20 0C is pumped from one storage tank to a reactor (density=878 kg/ m3 ). Volumetric flow rate of benzene is 9.5x 10-4 m3 /s. The difference in the elevations of the two unit is 40m. The tank whichserves as a source is open to the atmosphere while the tank which receives the benzene has a pressure of P2 kPa abs in the vapor space above the benzene. 1‐in, schedule‐40 steel pipe and 2‐in Sch‐40 steel pipe isused in suction and discharge line respectively. Total friction loss of the system given as 135 J/kg . Pressure gauges in the pipeline at the inlet and outlet of the pump read (P3) 34.5kPa and (P4) 1051.6kPa, respectively. Efficiency of pump is %75 a) Calculate the power of pump (kW). (Fluid Mechanics Question) (Please answer it detailed and step by step)
What is the developed coefficient of conductance of a tube-in-tube condenser having a water terminal temperature of 28.9°C and 18.3°C? The rate of water discharge from a 5.4mm copper alloy tubes 3.05 meters long are surrounded by steam flow of 97 kg/min at 104.4°C.
A single-effect evaporator is being used to concentrate10,000 kg/h of tomato juice from 5% total solids to 30% totalsolids. The juice enters the evaporator at 15°C. The evaporatoris operated with steam (80% quality) at 143.27 kPa. Thevacuum inside the evaporator allows the juice to boil at 75°C.Calculate (a) the steam requirements and (b) steam economyfor the process. Assume the condensate is discharged at 75°C.The specifi c heat of the liquid feed is 4.1 kJ/(kg°C) and theconcentrated product is 3.1 kJ/(kg°C). Make it in the form of an example solution spreadsheet .....
Steam with an enthalpy of 2168 kJ/kg enters a condenser at a rate of 10,000 kg/h. If the steam leaves the condenser with an enthalpy of 251 kJ/kg, determine the heat rejection rate. Provide complete solution, with diagram
a forward feed triple effect evaporator is used to fed 13608 kg/hr of NaOH solution containing 10 wt% solute. the entering feed temperature is 37.8°c. it is to be concentrated to a 50% NaOH solution. the steam used to enter at 58.6 kpa gage. the absolute pressure in the vapor space of the third effect is 6.76 kpa. the heat transfer coefficient are u1=6246, u2=3407, and u3=2271 w/m²k. all effects must have the same area. calculate the surface area and steam consumption Show steps and solutions .